Laser scanning confocal microscopy: a potential technique for the study of lithic microwear

The key problem restricting lithic microwear analysis is the lack of quantitative analysis to support qualitative assessments of different wear traces. This paper presents the reflective laser scanning confocal microscope (LSCM) as a new technique for the study of lithic microwear that has the potential to resolve this problem. Firstly, an example is presented that shows how the LSCM compares with conventional reflected light microscopy and scanning electron microscopy. This shows that images, rivalling that of the SEM, can be produced in similar timescales to conventional photomicrography and with no need for casting or sample preparation. The LSCM is also used to measure surface roughness of use-wear produced from working hide (dry, fresh and greasy), woodworking and antler working. This analysis demonstrates clear differences between the different wear polishes and the potential of the LSCM as a quantitative approach in lithic microwear research.     

Scanning electron microscopy of dry hide working tools: The role of abrasives and humidity in microwear polish formation

This paper presents the results of the scanning electron microscopy of a series of experimental tools designed to investigate the role of abrasive agents and humidity in microwear polish formation. The tools—35 end scrapers—were divided into four groups and used to work dry hide. It was found that both humidity and abrasive agents are two basic variables in the development of the microwear polish.     

QUANTIFICATION AND DISCRIMINATION OF LITHIC USE‐WEAR: SURFACE PROFILE MEASUREMENTS AND LENGTH‐SCALE FRACTAL ANALYSIS*

This experimental programme employs length‐scale analysis of measured profiles to quantitatively discriminate the surface textures of stone flakes manufactured from East Anglian chalk flint used on four contact materials (shell, wood, dry hide and soaked antler). It presents a method for evaluating texture characterization parameters based on their ability to discriminate wear types, and to determine a level of confidence to the discrimination, using the F‐test. The results of this experimental work demonstrate that relative lengths, over certain scale ranges, can discriminate the stone tool surface wear profiles produced by the different contact materials.     

Quantifying 3D Micro‐Surface Changes on Experimental Stones Used to Break Bones and Their Implications for the Analysis of Early Stone Age Pounding Tools

We present a new method to assess use‐wear formation processes of pounding tools used to break bones based on a combination of conventional microscopy, optical 3D surface measurements obtained with a confocal microscope and GIS analysis. The method involves 3D alignment and 3D surface change inspection techniques along with a surface morphometric characterization and 2D spatial pattern analysis, to measure the spatital distribution of significant changes in surface topography of pounding tools. Our results show that microscopic changes can be detected in the surfaces of hammers and anvils after bone breakage activities are performed. Use‐wear on the active elements (hammers made on basalt and quartzite) occurred over a larger area than was observed on the passive element (quartzite anvil), but the latter often exhibited deeper modifications. Tool surfaces generally developed smoother topography with increased use, but grain microfracture also appeared with greater frequency over time. This methodology offers highly accurate and statistically robust analyses of microscopic use‐wear traces that can be applied to the analysis of archaeological pounding tools.     

AN INTERIM REPORT OF THE STAR CARR MICROWEAR STUDY

Summary. This paper presents some preliminary observations based on the microwear analysis of 173 artefacts from the mesolithic site of Star Carr, near Scarborough, Yorkshire. One hundred discrete and utilized edges were identified by the presence of various microwear traces on 79 of the artefacts belonging to the following general types: scrapers, edge-damaged or marginally retouched blades and flakes, bilaterally backed blades (awls), burins, backed blades, axe resharpening flakes, denticulated or truncated blades and flakes, microliths, and cores. The microwear traces identified on the tools indicates that they were used in a variety of ways in the processing of hide, bone, wood, antler and meat. A comparison of wear-traces and tool shape has shown that there are morphological differences between scrapers used on hide and those used on bone, and also, that edge-damaged or marginally retouched blades were selected for use on the basis of their cross-sectional configuration.     

Slicing Cut Marks on Animal Bones: Diagnostics for Identifying Stone Tool Type and Raw Material

Abstract

Butchering implements leave identifying signatures on bones. From these signatures, it is possible to distinguish the different raw materials and types of chipped stone butchering tools. The results of recent experiments enable us to distinguish the different types of raw materials and tools used in the butchering process, in particular those implements that produce slicing cut marks. Three types of chipped stone tools (blades,flakes, and side scrapers) and raw materials (flint, obsidian, and quartzite), as well as issues relevant to lithic production and use were examined and tested. Silicone molds of cut marks produced by each of the instruments were made and subjected to analysis in light optical and scanning electron microscopes under various levels of magnification. The criteria used for distinguishing tool type, raw material, type of production and use characteristics of the respective cutting instruments are presented, as well as a discussion of the application of the experimental results to the Early Bronze Age I site of Afridar, Israel. The data from Afridar indicate that almost all of the butchering marks on animal bones from the site were made by stone tools, in particular haphazardly-made flakes.     

Discrimination of Ceramic Surface Finishing by Vertical Scanning Interferometry

Finishing techniques are significant markers of the technological ‘know‐how’ involved in the production of the traditional, clay‐based ceramic ware. In order to provide a reliable tool to discriminate among two main surface processing techniques—that is, smoothing and burnishing—vertical scanning interferometry (VSI), a recently developed non‐destructive technique for analysing the surface roughness and topography, is applied. The smoothed areas have an obvious roughness expressed by linear structures. The latter are made of parallel ridges and trenches with an average depth of 15–20 μm. Burnishing leads to a lower topography and a lower roughness compared to the smoothed surface section. VSI quantifies the spatial distribution of the surface building blocks, which consist of phyllosilicate aggregates of variable size. The statistical treatment of the roughness data obtained by VSI shows that the surface topography provides significant information on the pottery processing and a clear qualitative and quantitative discrimination between different surfaces. VSI supports the reconstitution of the chaîne opératoire for traditional ceramic pottery and the recognition of the surface finishing techniques.     

Occlusal microwear texture analysis and the diets of historical/prehistoric hunter‐gatherers

With the exception of few studies, occlusal microwear of pre‐agricultural modern humans has not been documented. In this study, microwear fabrics of samples from seven historic/prehistoric hunter‐gatherer populations with known and diverse dietary habits, representing mostly meat‐eaters from different environments, arctic/tundra (Tigara from Point Hope), cold‐steppe (Fuegians) and Mediterranean (Chumash), and mixed‐diet hunter‐gatherers from tropical climates (Andamanese and Khoe‐San from Matjes River, Riet River, and Oakhurst Shelter), were analysed to better understand how dietary differences affect microwear in these groups and to establish a reasonable comparative database for interpreting fossil hominins microwear. Significant microwear differences, related to diet and food preparation techniques, between the meat‐eaters and mixed‐diet hunter‐gatherers were detected. Finer scale differences within each of these dietary categories were also observed. Ethnographic accounts indicate that the Tigara and Andamanese ingested hard particles attached to their food as a result of their food preparation techniques; their microwear fabrics also reflect highly abrasive diets. On the other hand, as expected, the microwear signatures of the Chumash and Fuegians indicate a diet low in abrasives, reflecting their almost exclusive reliance on marine meat for subsistence and the low amounts of extraneous particles attached to this meat. The mixed‐diet Khoe‐San occupy an intermediate position between the Tigara and Andamanese on the one hand, and the Chumash and Fuegians on the other, with regard to the level of abrasives ingested. The Khoe‐San ate large amounts of hard plants, most likely responsible for abrading their enamel surface. Copyright © 2008 John Wiley & Sons, Ltd.     

Microwear analysis of experimental flint tools: a test case

Recent attempts to infer the functions of prehistoric stone tools have centred on the study of microscopic traces of wear on the surfaces of these tools. One method of “microwear analysis” involving high magnification and an incident light microscope is tested in this paper. Modern flint tools made and used in ways thought relevant to prehistory were produced by a lithic technologist and after cleaning given to the microwear specialist who attempted to infer their use. A high degree of agreement between inferred and actual uses was achieved and this encouraging result has important implications for the study of microwear on prehistoric tools where no such independent check is available.     

Flint and Quartzite: Distinguishing Raw Material Through Bone Cut Marks

Since the 1980s, several experimental analyses have been able to differentiate some lithic tool types and some of their raw materials according to the morphology of cut marks imprinted by such tools when used for butchering activities. Thus, metal tool use has been differentiated in contexts with an abundance of lithic tools, or even the use of hand axes has been documented in carcass processing, in contrast with simple unretouched or retouched flakes. As important as this information is, there are still other important aspects to be analysed. Can cut marks produced with different lithic raw material types be differentiated? Can cut marks made with different types of the same raw material type be characterized and differentiated? The objective of this study is to evaluate if cut marks resulting from the use of different flints and different quartzites are distinguishable from each other. In the present work, an experimental analysis of hundreds of cut marks produced by five types of flint and five varieties of quartzite was carried out. Microphotogrammetry and geometric–morphometric techniques were applied to analyse these cut marks. The results show that flint cut marks and quartzite cut marks can be characterized at the assemblage level. Different types of flint produced cut marks that were not significantly different from each other. Cut marks made with Olduvai Gorge quartzite were significantly different from those produced with a set comprising several other types of quartzites. Crystal size, which is larger in Olduvai Gorge quartzites (0.5 mm) than Spanish quartzites (177–250 μm), is discussed as being the main reason for these statistically significant differences. This documented intra‐sample and inter‐sample variance does not hinder the resolution of the approach to differentiate between these two generic raw material types and opens the door for the application of this method in archaeological contexts.     

An investigation of the fractal properties of flint microwear images

This paper reports on an investigation into the fractal dimensions of flint microwear images which has been carried out in an attempt to resolve the existing controversy over the possibility of identifying microwear types from visual inspection of high magnification images, and describes a new method for flint microwear image analysis based on fractal geometry. Fractal dimensions of surface images, which are known to relate well to human visual perception of roughness, have been computed for various types of microwear. No significant correlations have been found between the fractal properties of the digital flint images and the contacted materials.     

Defining and Characterizing Archaeological Quartzite: Sedimentary and Metamorphic Processes in the Lithic Assemblages of El Habario and El Arteu (Cantabrian Mountains,Northern Spain)

Quartzite was the second most‐often used lithic raw material in Europe in the Palaeolithic. However, this rock has not been characterized fully from the geo‐archaeological point of view. This study characterizes, defines and determines types of quartzite in northern Spain through a methodology that integrates petrography, digital image processing and X‐ray fluorescence. As a methodological foundation for the characterization of the material, it aims to open the possibility of discovering mechanisms of mobility, selection and management of quartzite by prehistoric societies. The types determined, based on the petrogenesis of the material, enable a better understanding of the archaeological sites of El Arteu and El Habario in the context of northern Spain in the Middle Palaeolithic.     

Microwear study of quartzite artefacts: preliminary results from the Middle Pleistocene site of Payre (South-eastern France)

Preliminary functional results obtained from the quartzite assemblage of the Early Middle Palaeolithic site of Payre (South-eastern France) are presented. In an area rich in flint, hominins at Payre also collected quartzite in their local environment, specifically along the Rhône River banks. Although the Payre lithic assemblage is largely composed of flint, quartzite was introduced in the site mainly as large cutting tools knapped outside. This fact pointed out an apparently highly differential treatment of the raw material types available in the region. A major concern is to understand the reason why. Is there any functional reason for the introduction of those artefacts, perhaps to perform specific activities related to the toughness of quartzite? Or is there any functional differentiation among the various raw materials? Use-wear analysis is a useful tool for better understanding human technological choices and strategies of lithic raw material management. Before attempting to extensively apply use-wear analysis on the quartzite assemblage, we analysed a limited sample to evaluate the general surface preservation. A specific experimental programme with the same local quartzite was carried out in order to provide a reliable comparative reference for interpreting use-wear evidence on archaeological implements. Methodological difficulties related to use-wear analysis applied to quartzite artefacts are also discussed. Both Optical light microscopy (OLM) and Scanning Electron Microscopy (SEM) were employed in this study; however, interpretations were elaborated considering principally SEM micro-graphs.The analysis of the archaeological material showed a good state of preservation of the surfaces with a low incidence of post-depositional alterations. The documented use-wear allowed us to identify the active edges, the kinematics and, more rarely, the worked material. Chopping activities were documented on two large artefacts suggesting a specific utility of those tools.     

EXPERIMENTAL IN VITRO DISSOLUTION OF THE DENTINE OF TEETH OF SUS SCROFA (MAMMALIA,SUIDAE): CHEMISTRY AND MICROSTRUCTURAL ALTERATIONS*

Alterations induced during the first step of fossilization are examined. Molars and premolars of a modern large mammal were crushed to expose fresh dentine. Fragments were placed in solutions of acids present in humus for 2 months. Changes in composition of the solutions were analysed. Micro‐ and nanostructural changes of fresh and etched dentine were observed with scanning electron and atomic force microscopes. The ion contents of the acetic acid solution are higher than those of oxalic and oxalic plus acetic acid solutions. Oxalic acid etching results in secondary deposits of oxalates on the exposed dentine. The composition of the soil in natural fossilization processes is a main factor in fossil preservation.     

A dental microwear study of seaweed‐eating and grazing sheep from Orkney

The potential of dental microwear for recognizing the use of seaweed as fodder in the past is explored through the analysis of microwear patterning in modern seaweed‐eating and grazing sheep from Orkney. Seaweed‐eating and grazing sheep are clearly distinguished on the basis of microscopic dental wear patterns. This reflects an emphasis on anterior‐posterior jaw movements and large pitted features in the seaweed‐eaters and can be attributed to the differing forces and/or masticatory movements required in the comminution of grasses and seaweed. Differences between seaweed‐eating and grazing individuals are maintained when the grazing group is expanded to include grazing sheep from Greenland and the Scottish borders. It is concluded that the microwear of seaweed‐eating sheep is highly distinctive and that dental microwear analysis potentially has a widespread application for identifying seaweed grazing within Scotland and the North Atlantic islands. Copyright © 2000 John Wiley & Sons, Ltd.     

Experimental study of aqueous fluid infiltration into quartzite: implications for the kinetics of fluid redistribution and grain growth driven by interfacial energy reduction

To investigate the kinetics of interfacial energy‐driven fluid infiltration, experiments were carried out in a quartzite–water system at 621–925°C and 0.8 GPa. Infiltration couples were made by juxtaposing presynthesized dry quartzite cylinders and fluid reservoirs. The infiltration process was confirmed by the presence of pores at the quartzite grain edges. As predicted from theoretical considerations and previous experiments, wetting fluids such as pure water and NaCl aqueous solution infiltrated into quartzite, whereas nonwetting CO₂‐rich fluids did not. Newly precipitated quartz layers at the surfaces of the infiltrated sample proved that infiltration took place by a dissolution–precipitation mechanism. The enhancement of grain growth by fluid infiltration was observed over the entire range of experimental temperatures. The fluid fraction, gauged by the porosity of the run products, increases at the infiltration front and then decreases towards the fluid reservoir to form a high‐porosity zone with a maximum porosity of 2.3–2.9%. As infiltration proceeds, the high‐porosity zone advances like a travelling wave. This porosity wave is probably caused by a grain curvature gradient resulting from preferential grain growth in the infiltrated part of the quartzite, perhaps combined with other factors. The infiltration kinetics were modelled with a steady‐state diffusion model over the high‐porosity zone. The solubility difference between dissolving and precipitating grains was deduced to be 2 × 10^?2?3 × 10^?1 wt %. The experimentally obtained infiltration rate of aqueous fluid in the steady‐state diffusion regime (2 ± 0.5 × 10^?8 m sec^?1 at 823°C) is much faster than the estimated metamorphic fluid flux rates, so that interfacial energy‐driven fluid redistribution in quartz‐rich layers could significantly contribute to the fluid flux in high‐grade metamorphism, at least over a short distance. Cathodoluminescence observations of the run products revealed that the grain growth of quartzite in the presence of fluid proceeds extensively, which would promote the chemical equilibration between fluid and rock more effectively than would volume diffusion in quartz crystals.     

ANALYSING ARCHAEOLOGICAL BASALT USING NON‐DESTRUCTIVE ENERGY‐DISPERSIVE X‐RAY FLUORESCENCE (EDXRF): EFFECTS OF POST‐DEPOSITIONAL CHEMICAL WEATHERING AND SAMPLE SIZE ON ANALYTICAL PRECISION*

Energy‐dispersive X‐ray fluorescence (EDXRF) has been commonly used to determine geological sources of volcanic glass artefacts, but its ability to discriminate between basaltic sources is less developed. We examine the precision and accuracy of non‐destructive EDXRF for basalt artefacts by analysing varying size and weathering characteristics. The experiments identified no appreciable effect in reproducibility or measured composition due to thickness (down to 1 mm) or natural weathering of pre‐contact flake scars for the 17 elements measured in this study. Samples with surface area less than 100 mm², however, show significant variability in measured composition and reproducibility.     

THE TECHNOLOGICAL AND TYPOLOGICAL BEHAVIOUR OF A NEANDERTHAL GROUP FROM EL SIDRÓN CAVE (ASTURIAS,SPAIN)

This paper presents the first detailed analysis of the lithic industry from El Sidrón Cave. Previously we have published other works concerning Anthropology and Palaeogenetics. The lithic assemblage contains 415 artefacts coming from both unofficial and official excavations and is largely flake‐based. The raw material derives from the immediate cave environment, and is mostly chert, with quartzite in a lesser proportion. To date, 67 artefacts have been refitted, including some tools and cores. The spatial distribution of the refitted lithic artefacts confirms, on the one hand, the unity of the assemblage and, on the other, its secondary context.